Multiple conduit



sept. l, 1931. I H. PARKER 1,821,234

MULTIPLE CONDUIT Filed Oct. 29, 1927 2 Sheets-Sheet 1 Sept. 1, 1931. H. PARKER 1,821,234 MULTIPLE CNDUIT Filed Oct. 29, 1927 2 Sheets-Sheet 2 Patented Sept. 1, 1931 Mira LsTAiTEs PATE Nr cries f lHOWARD PARKER., on BERLIN, Newy HAMPSHIRE, AssIGNoRy'ro'BRowN COMPANY, oF

" BERLIN, NEW HAMPSHIRE, A conroRAfrIoN or MAINEl y,

l y MULTIPLE CONDUIT Application filed October 29, 1,927. Serial No. 229,738.

This invention relates to sections of built. up multiple conduit comprising sections ofI single conduit secured together-in uniformly paced relation so that Vsuccessive section-s of 5 the multiple conduit may be readily joined.

end to end with corresponding individualv conduits-properly alined to form a continu` ous multiple conduit of any'desiredflength` While fthe invention applies to conduit secwork. In the latter case, the f conduit is.

assembled in position and concrete is poured on to fill up thespaces between the yindividualV conduits. Thus a continuous concrete structure may be made having ducts lined by the fiber conduits. For this and similaruses, a certain typel of conduit is especially adapted by reasonofl its relative lightness, strength, toughness and other desirable characteristics, as well as the relatively low cost 'of-'producing and handling it. Conduitofthis type mayv bevmade by rolling up a sheet of wet cellulosic pulp on itself in successive convolutions until the desired wall thickness is obtained. The internal diameter may be determined by the size of the vcylindrical mandrel on which the pulp sheet is wound. The wall of the ibertube is subjected to considerable pressure i during they winding so that each convolution of the pulp. sheetl is pitch or other ,equivalent waterproofing. liquid. .This increases the hardness and,

durability of-the'tube. The'saturated tube is however light Vin weight compared Avwith metal, tile or the like., Tubing of this kind tions offany suitable material,:it is more .is suitable `for mostl of the uses of metal pipe and tile conduit. In many-installations, such as fortelephone cables, powerf trans- ;mission lines, andthe like,it is desirable to lay a group of parallel conduits. If a fiberlined concrete structure be desired,""this can be made by assembling theindividual sec-y tions of-conduit with spacers to build up the desired number ofparallel continuous conduits, whereuponconcrete is poured'on to- This process, however, is open to several racticalob'ections as it is com arativel slow and 4therefore expensive in labor'costs. Furthermore, the 'tendency f of the hollow 'liber-piping tor float in wet' concreteor in casual waterV which may'collect in a trench or depression when the lconduit is being assembled, Lmakes theassembled conduits attimes diliicult to control and lto `keep in proper relative position. ln order to overcome these and other difficulties, l have devised animproved multiple conduit section which is relatively strong, is easily assembled, and in which the individual. conduit sections are .spaced with comparativek accuracy so that may be all'alined at once without the-diffii culty ofliaving to force some of the individual conduit ends laterally to bring them into alinement. This is` of. great importance where a considerable number of parallel conduit sections are assembled in a multiple conduit section for if ythe individual conduit sections of each multiple section `are not accurately spaced, the joining together -of the ends of successive multiplev conduitv sections becomes a difficult and time-consum- Y ing operation.l By this invention, spacers are provided whichare light, accurate, and easily applied tohold the individual conduit sections in correct spaced relation inv a.

vmultiple conduit section. The spacers mayA kalso be madewithout metal of any kind, an

important feature where the conduit is used for electrical power transmission cables, and may be made of waste stock which would otherwise be a totaliloss. l l

For a more complete understanding of the fill the spaces between the lines off conduit.

invention, reference is had to the disclosure thereof in the following description and to the drawings, of which,-

Figure 1 is a cross sectional view of a double conduit illustrating an embodiment of my invention.

Figure 2 is a transverse section of a quadruple conduit. n

Figure Bis a perspective View of a piece of short -length oversized conduit in the course of preparation for -use in constructing spacing elements.

Figure 4L shows an improved single spacing unit embodying the invention.

Figure 5 illustrates a trough suitable 7for assembling sections of singleconduit to form a multiplel conduit;

Figure 6 shows -a multiple spacing unit adapted for use with four sections of single conduit.

Figure 7 is a transverse section of multiple conduit comprising sixteen single conduits.

Figure 81 is a fragmentary plan view of the multiple conduit illustrated in'Figure 7,

this gureshowing a preferred method ofr uniting groups of single conduit.

According to the invention, sections of multiple conduit may be constructed by assembling any desired numberY of sections of single conduit as for example two in Figure 1, and four in Figure 2. Since in laying the'conduit, it isneeessaryxthat the ends of one .section of multiple conduit interfit with'the ends of the-next adjoining `section of multiple conduit, it is important that the 'between each pair of single conduits, these spacing-elements vbeing in fitting engagement withv a considerable arc of the peripheryof eachv of thev conduits on either side of the lineV of centers and having a uniform yminimum thickness or diameter between oppositeconcave faces. It is also a ypurpose of the invention to, provide spacing elements made largely of waste products of the mill. -As shown in Figure 1,a double conduit may be constructed vby assembling a pair of single conduits 10 with a spacing element between. The latter may be made of a pair of sectors 11 cut from a short.

length of oversized conduit which has van internal curvature'substantially equal to the external curvature ofthe conduits 10. The sector 11 ispreferably of substantial width soas to .engage vthe peripheral surface of the conduit 10 over a Vsubstantial arc not .f...greate'r-than 180. The seetorsll arepreferably secured to an intermediate. connecting block 12 which may be of any desired thickness, according to the spacing desired in the multiple conduit. The blocks in any one lot, however, are preferably of accurately uniform thickness. In order to prevent rocking of the sectors 11 on the faces of the blocks 12, flat portions 13 may be provided on the convex surface of each sector 11. Such flat surfaces may be formed by milling the outside of a short length of oversized conduit, a` central tongue or ridge 14 being preferably left projecting from each flat face 13. The blocks12 may be channeled as at 15 to receive the tongues 111 of the sectors V'12. This results in a spacing element which keeps its shape and alinement evenunder severe usage, and also lmaterially aids in holding the conduits 10 accurately in `their relative positions. In order to mill the flat 4faces 13, a short piece of conduit such -as is illustrated in Figure 3 is placed on a mandrel which -lits the bore thereof. The vinner diameters of brous conduits vof the type previously described, are usually Very closely luniform for a given size,sinee the :pulp sheet Iforming the conduit is wound up on metal mandrels of uni-form diameter and the sections 'of conduit are carefully dried under uniform conditions so that there, is little or no distortion in interior diameter caused by knonuniform shrinkage. The ex teriorI diameters, however, are subject ,to more or less variation depending onthe amount ofipulp which is wound onto the mandrel in yformingthe tube. In milling the short lengthconduit as shown in -Figure 3, the milling cutters are located at a definite predetermined distance from the center of the vmandrel holding thepiece of fconduit so that the .plane of each face 13 is A found in a Vplane bisectingthe tongues `15,

is very closely uniform Vfor all the spacing Aelementsthusmade in spite of variations in the wall thicknessof the oversized conduit from which the sectors 11 are taken. Spacing element-s ofxthis type as illustrated in Figure 4, may be used in the assembling of any number of conduitsections, the elements being interposed between successive single conduits in a row, such as isr shown in Figure 5 and also between -adjacent conduits of successive rows where 'a 'multiple conduit is built upof more'than` one row. .For example, a multiple conduit composed of sixteen single'conduitsasfshown in Figure 7 could be constructed by usingmultiples f of twenty-four of such spacing elements. Figures 2 and 6 illustrate a slightly modied form of spacing element which amounts to four single elements joined in one. These quadruple spacing elements may comprise sectors 17 of short length oversized conduit, the sectors being preferably about 180. These are arranged as shown in Figure 6 and spaced by blocks 12, pegs or other fastening means 16 being employed to secure the sectors 17 to the blocks 12. The sectors 17 being approximately 180o are adapted to receive the single conduits and to engage the exterior surface thereof over a substantial angle of their periphery. This makes for stability and stren th in the multiple conduit. A larger arc t an 180 is avoided since such an arc would necessitate the threading of the conduits 10 through the bore of the sect-ors 17 instead of permitting the lateral introduction of the conduits thereagainst.

In assembling sections of single conduit to form sections of multiple conduit, a suitable box or trough 18 may be provided, the sides of the trough having apertures or notches 19 to facilitate the manipulation of a tie member 20 to be passed around the assembled conduits. The tie member is laid on the bottom of the trough with the ends extending out through the notches 19. The single conduits are then assembled with spacing elements between them. The structure may be strengthened by smearing a small amount of adhesive, such as molten pitch, on the concave faces of the sectors 11 before they are brought into engagement with the single conduits 10. When the conduits are in position with their spacers as shown in Figure 5, the ends of the tie member 20 are brought together and fastened in a desired manner. As illustrated in Figure 5, the tie member may consist of a steel band, the ends of which may be secured as by a clip 21 which is crimped to hold the ends of the band tightly. Any other suitable strand material may, however, be employed instead of the steel band. For larger units of multiple conduit such as shown in Figure 7, groups of eight single conduit may be assembled, preferably by the use of multiple spacing units such as shown in Figure 6 supplemented by additional single units as shown in Figure 4. Two groups of eight conduits are secured together with spacers between, as shown in Figure 8, by threading tie members 2O between the rows of each group. This facilitates the assembling of the conduit and results in a strong and satisfactory multiple unit.

The simplicity of the spacing units and 'the method of assembling the conduits makes it possible for the assembling to be done where they are to be used, thus avoiding the shipment of comparatively bulky multiple units.k The individual conduits Amay be shipped as such and assembled as used in the-vicinity of the installation. Continuous multiple conduit constructed by joining multiple conduit sections as herein described, end to end, is superior to continuous multiple conduit formed by building up single conduit in the course of installation, the former having considerably greater structural .rigidity and strength` and thus being free from tendencies to spread or upset. y

Having thus described certainembodi ments of my invention, it should be evident to those skilled in the art that various changes and modifications might be made therein without departing fromits spirit or scope as defined by the appended claims.

I claim 1. A spacer for multiple conduit, comprising a pair of sectors of short-length oversize conduit, each said sector being not over 1800, means for-securing the sectors together with concave faces presentedoutwardly and the centers of curvature spaced a predetermined distance from each other.

2. A vspacer for multiple conduit, comprisinga pair of sectors of not over 180o of short-length oversize conduit, arranged with convex faces opposed, said convex faces each having a flat portion defining a plane at a predetermined distance `from the center of curvature of its respective sector regardless of the wall thickness of the sector, a connecting piece arranged between said flat portions, and means for securing said sectors to said connecting piece.

3. A spacer for multiple conduit, comprising a pair of sectors of not over 180 of short-length oversize conduit, each sector having a flat portion on its convex face and a tongue arranged centrally of the flat portion and extending parallel to the axis of the conduit section, a connecting piece comprising a block having parallel side faces,

each side face having a central groove' extending longitudinally of the block, each side face and groove being in fitted engagement with one of said lflat portions ,and its tongue, and means for securing the sectors and block together.

4. A spacer for multiple conduit, comprising a pair of `approximately quadrant sectors of short-length oversize conduit, a

connecting block between and in contact withthe convex sides of said sectors, said block having a central groove extending lengthwise in each contacting face, said sectors each having a fiat portion in contact f with a grooved face of the block, said flat portion having a tongue thereon entering the groove, and wooden fastening pegs pass- A of short-length oversize conduit, arranged symmetrically with concave faces outward, a block between each pair of adjacent sectors on their line of centers, said blocks and sectors having flat face portions in mutual engagement, and means for securing the sectors and blocks in position. i

6. A section of multiple conduit comprising a plurality of assembled parallel sections of single conduit, a spacing unit between each pair of adjacent sections, said spacing unit comprising a pair of sectors of oversize conduit and a block to which said sectors are secured, each sector being not over and arranged with concave faces outward, and a exible tension member surrounding the assembled sections and holding them against their contiguous spacing units.

7. A section of multiple conduit comprising a plurality of assembled parallel sections of single conduit, means for spacing single conduit sections uniformly, said spacing means comprising a unit between each pair of adjacent conduits composed of a block and a pair of sectors of short length oversize conduit secured to said block with concave faces out, each sector having a fiat portion abutting a face of the block, the .minimum distance between said concave faces being predetermined regardless of the wall thickness of the sectors, and tie means surrounding the multiple section. Y

8. A multiple conduit section comprising g four spaced rows of spaced single conduit,

the spacing between the rows and single conduits being uniform, a spacing unit between each pair of'adjacent sections of single conduit, liexible tie members surrounding the first and second rows of sections to form a vgroup thereof, flexible tie members surrounding the third and fourth rows of sections to form aa second group thereof, and tie members sur-rounding ythe second and third rows of sections to bind together the two groups into a four-row multiple section.

9. A multiple conduit section comprising a Aplurality of sections of single conduit assembled in parallel uniformly spaced relation, a. spacing unit between each pair of vadjacent single conduits, each spacing unit engaging the peripheries of the pair of sections in contact therewith over a substantial arc not over 1800, the areas of contact being substantially bisected by the line of centers of said pair of sections, and a flexible tie member surrounding said multiple section.

In testimony whereof I have affixed my signature.

HOWARD PARKER.H 

